Overview of Acromegaly Treatment
While surgery remains the treatment of choice, the role of pharmacologic agents has expanded as the need for tight biochemical control becomes clear1.
Long-acting somatostatin analogues, such as Sandostatin® LAR Depot (octreotide acetate for injectable suspension), remain the mainstay of medical therapy, as highlighted in acromegaly treatment guidelines (PDF 93KB) published by the American Association of Clinical Endocrinologists (AACE)2.
In this section, you will find information about:
The Goals of Therapy
The primary goals of therapy are to control several key pathophysiologic aspects of acromegaly:
- Removal of or reduction of the tumor mass
- Control of both GH and IGF-1 levels*
- Amelioration of the clinical signs and symptoms of acromegaly
* Sandostatin® LAR Depot suppresses GH hypersecretion to <2.5 ng/mL in 66% of patients and normalizes IGF-1 in 67% of patients3.
Treatment can ameliorate many of the clinical signs and symptoms in patients with acromegaly. Even after treatment, many debilitating sequelae, eg, bone and cartilage lesions and organomegaly, are not reversed; however, soft tissue changes usually resolve2. Normalizing plasma IGF-1 and GH concentrations drastically reduces symptoms of the disease, and a reduction in GH can affect mortality as GH levels can be predictive of mortality in acromegaly2,4-6.
AACE Treatment Guidelines for Acromegaly
Emerging information about treatment options has necessitated a reevaluation of the management of acromegaly. In its guidelines (PDF 93KB), the AACE makes recommendations for effectively managing acromegaly that will help guide the practicing physician. They note that acromegaly is characterized by hypersecretion of GH, which in turn stimulates the production of IGF-1. Both GH and IGF-1 contribute to the manifestations of acromegaly2.
Morbidity in acromegaly is caused by metabolic abnormalities associated with excess GH. Many acromegaly morbidities can be reversed, at least in part, with appropriate treatment, emphasizing the need for optimal disease management. Importantly, the AACE guidelines recognize that the normalization of biochemical parameters is necessary for the effective treatment of acromegaly. Thus, the need for early diagnosis and effective treatment is critical2,5,6.
AACE Acromegaly Treatment Algorithm2
Recommended scheme for management of GH-producing pituitary adenomas. GHA=growth hormone antagonist; IGF-1=insulin-like growth factor-1; Nl=normal; SSA=somatostatin analogue; XRT=radiation therapy. GH levels are taken post OGTT.
Reprinted with permission from the American Association of Clinical Endocrinologists as featured in Endocrine Practice, volume 10, 2004, page 219. Please see full guidelines for treatment recommendations in select patients.
Choosing a Treatment Option
The following facts need to be kept in mind when considering different treatment options:
- Treatment protocols continue to evolve, and the advantages and disadvantages of each may change, based on factors such as the advent of novel delivery systems, cost, advances in radiosurgery or medical therapy, and a better understanding of the disease process7
- As the need for stricter criteria for biochemical control of GH (<2.5 ng/mL) and normalization of IGF-1 levels in the management of acromegaly are becoming more widely accepted and actively determined, it will probably become more common for several therapeutic agents, rather than a single treatment option, to be part of a treatment strategy for effectively controlling this disease8
- The value of a particular therapeutic modality should be assessed in conjunction with its potential influence on subsequent therapy; for example, reduction of tumor mass and GH output by surgery may increase the effectiveness of subsequent radiation therapy8
Important Safety Information
Carcinoid Syndrome:
Sandostatin® LAR Depot (octreotide acetate for injectable suspension) is indicated for long-term treatment of the severe diarrhea and flushing episodes associated with metastatic carcinoid tumors and for the long-term treatment of the profuse watery diarrhea associated with VIP-secreting tumors in patients in whom initial treatment with immediate release Sandostatin® (octreotide acetate) Injection has been shown to be effective and tolerated.
Important Safety Information:
As with immediate release Sandostatin® Injection, the most frequently reported drug-related adverse events were biliary disorders (62%), gastrointestinal disorders (14% to 38%), and injection-site pain (20% to 50%). Hypoglycemia (4%), hyperglycemia (27%), sinus bradycardia (19%), conduction abnormalities (9%), and arrhythmias (3%) have been reported.
The controlled clinical trials that support the marketing clearance for Sandostatin® LAR Depot did not include determination of effect on tumor size or rate of growth. Sandostatin® LAR Depot is not indicated for tumor shrinkage.
Acromegaly
Sandostatin® LAR Depot (octreotide acetate for injectable suspension) is indicated for long-term maintenance therapy in acromegalic patients who have had an inadequate response to surgery and/or radiotherapy, or for whom surgery and/or radiotherapy is not an option. The goal of treatment in acromegaly is to reduce GH and IGF-1 levels to normal.
Important Safety Information:
As with immediate release Sandostatin® Injection, the most frequently reported drug-related adverse events were biliary disorders (52%), gastrointestinal disorders (7% to 36%), and injection-site pain (2% to 11%). Hypoglycemia (2%), hyperglycemia (15%), and hypothyroidism (2%) have been reported. While not measured in acromegalic patients receiving Sandostatin® LAR Depot, ECG changes have been reported in patients receiving immediate release Sandostatin® Injection; the degree to which these abnormalities are related to octreotide acetate is not clear, as many acromegalics have cardiovascular disease. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.
